Deciphering the Keys for High Enantioselectivity in Hypervalent Iodine-Catalyzed 1,2-Difunctionalization: Improved Synthesis of Ishihara-Muniz Precatalysts

In the course of upscaling the synthesis of enantiopure aryliodine precatalysts, we detected an unreported meso form of the catalysts for the first time. A new scalable route was developed to avoid epimerization of the lactamide arms, providing syntheses of the precatalysts that are both more effective and much less time-consuming. The catalysts obtained with these synthetic procedures have been employed in some published reactions, reaching the maximum ee ever reported.

Automated summary

A previously unreported meso form of the catalysts was discovered during the upscaling process. A new scalable route was developed to prevent epimerization of the lactamide arms, leading to more effective and time-saving syntheses of the precatalysts. The catalysts obtained from these procedures have been utilized in published reactions, achieving the highest enantiomeric excess ever reported.